Elevated concrete spans or decks are necessary in the construction of bridges, multi-story buildings, and other structures such as culverts and falsework applications. Such spans are often constructed on site. In order to construct such spans, concrete forms are built between two or more adjacent support beams or girders. The concrete form floor can be constructed from corrugated metal sheets (referred to in the art as "stay in place" or "SIP" decking) or other materials such as plywood which are placed on and extend between the two adjacent support beams or girders. The distance between the adjacent support beams determines to a large extent the characteristics of the material used to construct the form floor. Where the distance between the adjacent support beams is relatively small, thinner form floor materials can be used by simply placing the form floor materials across the support beams. If the distance between the support beams is increased, and the ability of the form floor to support the weight of the concrete is exceeded, the builder must decide whether to use thicker form floor material, which is more expensive than thinner materials, or to use additional means for supporting the bottom of the form floor.
The use of additional support for the form floor has been particularly desirable when using SIP decking in view of the high cost difference between the thin and thick SIP decking. In the past, however, the cost of providing the additional support necessary to be able to use thin SIP decking was also very high. Because each bridge, building or other structure is unique in many aspects, not the least of which is in the number of and spacing between span support beams, it has been necessary to construct special timber bracing for supporting a shoring timber placed between the span support beams for supporting the center of the form floor. Because the timbers for the bracing are cut to size and fitted depending upon the dimensions of the particular bridge, they generally cannot be reused. Further, a significant element of the cost of providing the additional support arises from the many manhours required to cut the timbers, construct the bracing, and disassemble when the job is completed. An adjustable, reusable form brace is described in my U.S. Pat. No. 4,880,203. This form brace has two legs which are pivotally connected by a cradle which supports the central portion of the form deck between the two support beams. However, in some situations the two support beams may be spaced too far apart for this brace to be useful.
Therefore, the need exists for a reusable form brace which can be used to support a shoring member placed beneath the form floor between the two support beams, which is adjustable in height to permit use in many different environments, and which is easy to erect and disassemble.